The present disclosure relates generally to measurement fixtures and, more particularly, to fixtures capable of measuring fastener length changes.
Varieties of fasteners are utilized in several industries to mechanically affix two or more objects together. For example, automobiles require the use of many different fasteners to join together different vehicle components. As a result, it may be important to analyze fastener characteristics both before and after tightening or attaching to ensure the quality of joints. Fastener length may be measured to analyze the stretch of fasteners after tightening or attaching the fastener to assess torque set point and bolt relaxation. Such information may provide insight to axial tension in order to assess assigned torque values and give confidence that a torque setting on process equipment is creating a desired axial tension in the fastener. Additionally, length measurements may provide bolt relaxation data to determine how fastened joint characteristics change over time.
Many procedures for detecting and measuring fastener stretch involve the use of elaborate and expensive ultrasonic equipment, and can be time and resource intensive. Additionally, such procedures may require the processing or changing of fastener surface characteristics rendering them unfit for use on a completed vehicle or other finished product.